RockSchmidt - Rebound Hammer for Rock Testing

For many years Proceq’s Original Schmidt hammers originally designed for non-destructive testing of concrete structures have been used for rock testing. With the release of the new RockSchmidt test hammers, Proceq presents the first rebound hammers adapted specifically to the extremely varied rock testing application.

The RockSchmidt incorporates statistical methods based on ASTM and ISRM recommendations and also provides the user with the freedom to define his own statistical process for determining a rebound number.

All data is stored on the instrument and may be downloaded to a PC later. The world’s most advanced rebound hammer, with unmatched dispersion characteristics, durability and measuring range has now been fully adapted for rock testing.

Two models are available. RockSchmidt Type N with standard impact energy is most suited to field testing and RockSchmidt Type L with low impact energy as specified by ASTM for testing cores.

Applications

• Geomorphological applications which investigate the bulk hardness properties of a rock outcrop
• Prediction of weathering grades
• Correlation to Unconfined (or Uniaxial) Compressive Strength (UCS)
• Correlation to Young’s Modulus
• Prediction of penetration rates for tunnel boring machines and rotary drum cutters
• Testing on cores and blocks

Features

The following features of the hammer make it ideal for rock testing applications:

Impact Angle Independence

• The rebound value is independent of the impact direction.

Optimized for Field Work

• Tighter sealing against dirt and dust intrusion for longer life.
• Significantly lighter and more ergonomic than the classic Schmidt hammer.
• A large number of readings can be saved and downloaded later to a PC.

Preset Statistics

• Statistics methods recommended by ISRM and ASTM are implemented into the hammer for automatic calculation of the rebound number.
• The option is also there to define a user specific statistics method.

Unconfined Compressive Strength

• ISRM recommends a correlation between UCS and the rebound value based on the formula UCS = aebR (where R is the rebound value).
• A correlation in this format may be defined in the PC software and downloaded onto the RockSchmidt.

Young’s (E-) Modulus

• ISRM recommends a correlation between elastic modulus and the rebound value based on the formula Et = cedR (where R is the rebound value).
• A correlation in this format may be defined in the software and downloaded onto the RockSchmidt.

Weathering Grade

• Impacting on the same location twice can be used to correlate to weathering grade.
• The ISRM recommended method has been included in the device.

Technical Specifications

Rock Testing Application Guide